Practical Definition and 323 Threads

I need a 10-15 : 1 step-down transformer for an electrolysis project. It needs to be capable of about 150A. I have an old ex-military transformer/rectifier, but it outputs 200A at upto 230V DC. It has a humungous transformer in it , and some banks of BIG diodes, so if I get a variac from ebay...

I was making a PCB drilling machine at home with my brother, and came across this mathematical? problem. I needed to fix the drill machine. But I needed to determine where should it be fixed so that I could drill largest possible PCB boards. In other words, find the value of x so that you...

Ok, I am wondering if its possible for me to calculate how much force or pressure I can take from carrying or moving something based on what I can already move. Is it possible to predict how much pressure I can take on my hands, or how much I can potentially create? For example (not...

Firstly, an open statement to everyone in this forum. I am in search of some answers to questions I have so that I may have a better understanding of this research. For this reason I have posted this so that through all of you my lack of education or some may refer to ignorance I may be...

Would fusion make for practical applications in high speed interplanetary propulsion? Or would beamed propulsion be better?

I hear a lot that group theory is important to condensed matter physics. Does it have any practical use? Like if I were to do industry work in materials, would I ever use it? Is it important enough to take a full course on abstract algebra?

Homework Statement So I have to wire the circuit and find R2 by only making another voltage measurement. We know that R3 is equal to 1000 ohms. Homework Equations The Attempt at a Solution So I was thinking that you can find the voltage of R3 and the find the current going...

I don't know where to ask this question, but anyways, since it was asked in an exam, so finding out the correct answer afterwards is a moral responsibility as a homework. So here I am. My question is whether the compound 2-Hydroxy-5-nitrobenzaldehyde (Did I named correctly?) gives positive...

Homework Statement Compare theoretical predictions for frequency response of a mass spring damper system with analytical test data. 1.) Carry out free response tests and use data to calculate damping ratio, damped and natural frequencies and damping coefficient and spring stiffness...

Does Ohms Law have practical limits? For example:A piece of steel wire of length of length 10um and of CSA 20E-10. Can we calculate the resistance of such a tiny piece of wire (resistor) in the usual way? thanks

As a quick heads up, I'm buried over my head in an imager project, and the portion that has given me the most headache is the UV source. Essentially, I need the source to make nice little 13 micron dots in the 405 nm range. I've been assured by a pair of vendors that this is an easy matter...

I'm not a professional in any scientific field just an avid consumer of popular science writing. I ran into a mention of magnetic monopoles awhile back and have been trying to dig up the answer to a few questions. Thus far I have failed so I decided to ask here. OK I understand magnetic...

"Practical" astrophysics. Hi, just a lowly undergrad hoping for some of the wisdom here to rub off. I have always had a keen interest in astrophysics and have considered giving a colder look at long-term prospects for an academic path in theory/computation in said field. Long-term stability...

I am an electrical engineering student currently in my pre-final year. I recently entered some robotics and circuit design competitions with my friends, and found the experience quite satisfying, applying the principles and theory I learned in the past 2 years for the very first time...

how can i find input and output impedance of a ce amplifier- (voltage divider )..suggest practical methods?

Dear all, Just as the title says - is there a practical way to make homemade 3% hydrogen peroxide? I'm looking to move to a remote section of Texas where medical help may be hours away and I know how H2O2 can prevent serious infections and has other medical purposes. Any help is...

Not sure if this is OT for the cosmology forum.. pls move if so. I'm wondering about examples of where cosmology science has helped in a practical way. Not being facetious.. genuinely curious (and I think knowledge for knowledge sake is almost always a good thing). Cosmology has helped...

Homework Statement A practical current source has a current of 22 A. Loading the source with 50 \Omega results in terminal voltage of 390.3 V. Obtain the source constants, I and R.Homework Equations V=I\times RThe Attempt at a Solution In my clumsy picture below, shouldn't I_{load} be replaced...

I need to give a short presentation about Colorimetry in my chemistry class. I plan on using the first five minutes giving an example procedure about determining the concentration using MicroLAB's spectrophotometer hardware in our lab. I would like to use that last five minutes of my...

Homework Statement the Hamiltonian of a free particle in an electromagnetic field is, H=H_{free} + H_{int} + \frac{q^2 A^2}{2mc^2} where the free Hamiltonian is just {p^2}/{2m} and the interaction Hamiltonian is, H_{int} (x) = -\frac{q}{mc}p\cdot A + q A_0 Show that the last term in...

I discovered your site yesterday, and have been fortunate to find such fine quality and detailed information on the Japan situation. Forgive me if I missed this already, but I have a few questions on actually living in Tokyo - I would much appreciate any responses: 1. The radiation level...

Need help with a physics practical to do with slingshots!? Basically I am doing a project on slingshots, we are allowed to investigate any areas do do with physics, however I need some ideas, I was hoping I could change a couple of variables and measure things. my idea was to change the...

Need help with a physics practical to do with slingshots!? Basically I am doing a project on slingshots, we are allowed to investigate any areas do do with physics, however I need some ideas, I was hoping I could change a couple of variables and measure things. my idea was to change the...

Hi can you please tell me the practical meaning of LIMITS...?

I have to perform a "lab practical" tomorrow for my E&M class and it involves using a multimeter to determine what is inside a "black box" - either a battery/resistor combo or a capacitor. Homework Statement Taken from the lab practical write-up: "You’ll be given a box with two...

Homework Statement Does anyone know what applications has Meissner effect? I have search on the internet but I did not find much only that the effect is not really of great practical use because it only occurs with superconductors, most effectively with type 1 supercondustors which have to...

Where we can find Limit Cycles Phenomena in Practice, I mean in which class of machines?

Hi there! So here's the deal. I'm restoring a friend's old Philco radio for his 1968 Mustang. This includes changing out the internals to tune FM instead of AM. The old AM internals include a set of three inductor coils with magnetic cores that move in and out of the coils as you turn the...

I am a high school senior preparing to choose what i shall study at a tertiary level. For many years i have had an interest in mathematics and theoretical physics. When i was younger i read brian greene, hawking and Randall. Yet i am now well aware that the theoretical aspects of science are...

Hello, I have the following question, I am trying to build a home made hot air gun for electronics soldering, my approach was with a modified Microwave oven transformer, multifilar 12mmxmm copper cables, and a 15cm stainless steel tube, the air is pumped from a powerful aquarium air pump. The...

Hey all, I'm trying to prepare for an upcoming Physics lab practical, but I'm having a hard time trying to figure this thing out. I'm not a Physics major, and I really don't have the "eye" that some other people have on what comes to Physics problems. I'm hoping that somebody could help me...

Hi... Hope i 'll get the good result that where we practically use the binomial and poisson distribution in the field of engineering...

Homework Statement I know that Rolle's Theorem states that if the function f is continuous on the closed interval [a,b] and differentiable on the open interval (a,b), and if f(a)=f(b) then there is at least one number c in (a,b) such that f'(c)=0. I want to know if there are any practical...

I need to take one more course for my EE Bachelors degree in one of three specialized areas: Signal Processing, Controls, or Communications. I know all three of these are very much related, but I am finding Signal Processing by far the most fascinating field out of the three. The problem is...

Homework Statement In order to increase resolution of the diffraction gratings we can use them in higher orders of diffraction. What is the practical limit on using very high orders of diffraction? Homework Equations R = \lambda / \Delta\lambda = Nm The Attempt at a Solution I...

Hi, Anyone has had experience with UAV control/signal design can tell me what is the typical flight speed (surveillance UAV), control range, link speed and control delay like? (Sorry, I am not a very good engineering student, furthermore control and signal not my discipline... I can only...

So I've read the highest skydive occurred from a balloon and the entire jump lasted on the order of 10s of minutes. Heres my question: How the do you know where your going to land? The Earth rotates at ~1000mi per hour that's 12 mi per minute or 2.7 miles per 10 secs. So did these people use...

hi all- having a strange (perhaps expected?) problem inserting a BBO into the optical path of a TiSaph fs laser. the issue is that i can achieve strong SHG output, but only with *severe* spatial distortion of the pulse shape. has anyone had experience/encountered this issue in an...

So we need to make a practical report and I'm not sure how to do it. I've learned the basics like lift equals weight and thrust equals drag.. and then the teacher made a model wind tunnel in class, we then got air speed(km/h) and its mass(g) etc. for it then we had to convert them to life and...

Hi guys, As somebody who likes to learn and understand everyday problems I've really hit a wall... I learned differentiation, integration and limits in my undergrad course, passed the exams etc but the way it was taught was pretty bad, nobody ever gave us "real life" examples. Personally...

Homework Statement [PLAIN]http://img186.imageshack.us/img186/6260/physicsquestion.jpg Homework Equations Not sure...? The Attempt at a Solution I believe the answer should be A or B. I'm thinking the live and Earth wires will form a complete circuit. Since there is very...

I am not sure if this is the right section but I thought you physicists may be able to give me an example. I am demonstrating the usefulness of the phi function and finding the last two digits of 107^{999999999} I am just wonder where in physics or astronomy such a massive number would come...

what is the practical use of the concept of band gap other than classification between material? can free carrier absorption be manipulated by changing band gaps?

hi, i am interested in nuclear physics but i don't really want to delve into the complexity of it, so could someone please give me an idea of the practical approach to making a breeder reactor, i do not intend to build one, i just would like to know how i would do it if did want to build one...

What are practical applications of the gamma function?

1. The use of a flimsy retort stand meant that when the pendulum was in the motion the retort stand was also swaying slightly. Explain this. 2. p=mv, torque=rmg 3. I am a bit stumped on this one. My teacher suggested I look into the torque of the pendulum - the friction at the...

Homework Statement To measure how far below the ocean surface a bird dives to catch a fish, a scientist uses a method originated by Lord Kelvin. He dusts the interiors of plastic tubes with powdered sugar and then seals one end of each tube. He captures the bird at nighttime in its nest and...

Hello, I have designed a magnetic circuit.. C core with an air gap. I calculated the circuit as well as doing a simulation on it using FEMM software. The core is from 1018 steel. My calculation and simulation gave almost similar result.. So, there is no problem in my calculation or...

So, I just received my 3x barlow lens in the mail and let my scope sit outside for two hours to adjust..later I realize the humidity is 80-90% and my scope (6" dob) is literally dripping. Other than moving to Arizona, is there a practical solution to this problem?

http://arxiv.org/abs/1003.2967 Immanuel Kant on Supersymmetry: A Practical Evaluation Alexander Unzicker 4 pages (Submitted on 15 Mar 2010) "A short review of the motivations for supersymmetry in astrophysics and particle physics is given. Despite the amount of theoretical research...